Intelligent terminals have become a part of people's life. Making calls, sending short message service (SMS) messages, accessing the Internet, and the like by using intelligent terminals are all common applications. However, in a use process, a problem of poor signal quality is frequently encountered. In particular, in a call process, if signal quality is poor, a problem of very poor call quality or even call drop or call interruption is generally caused, and great inconvenience is caused to a user's life.